反应详情

温度

65 °C

A stirred mixture of diethyl 3,3-dimethoxycyclobutanedicarboxylate (10.36 g, 39.8 mmol) in acetone (95 ml) and p-toluenesulphonic acid (1.38 g, 8.02 mmol) was heated to 65° C. overnight. Further p-toluenesulphonic acid (200 mg, 1.16 mmol) and acetone (15 ml) were added and the temperature raised to 75° C. for 2 hours. The reaction was cooled to room temperature. The mixture was neutralised with aqueous sodium bicarbonate. Water (15 ml) was added and then extracted with dichloromethane (3×10 ml). The extracts were dried over magnesium sulphate, filtered and evaporated in vacuo to give a brown oil. The crude oil was distilled (bulb-to-bulb) to give diethyl 3,3-dicarboxycyclobutanone as an oil, b.p. 150-155° C./0.1 mm.

1. temperaturethe temperature raised to 75° C. for 2 hours
2. temperatureThe reaction was cooled to room temperature
3. extractionextracted with dichloromethane (3×10 ml)
4. dry with materialThe extracts were dried over magnesium sulphate
5. filtrationfiltered
6. customevaporated in vacuo
7. customto give a brown oil
8. distillationThe crude oil was distilled (bulb-to-bulb)